Systems, devices, and methods for electrical stimulation using feedback to adjust stimulation parameters

ABSTRACT

An electrical stimulation system includes a control module that provides electrical stimulation signals to an electrical stimulation lead coupled to the control module for stimulation of patient tissue. The system also includes a sensor to be disposed on or within the body of the patient and to measure a biosignal; and a processor to communicate with the sensor to receive the biosignal and to generate an adjustment to one or more of the stimulation parameters based on the biosignal. The adjustment can be configured and arranged to steer the electrical stimulation signals to stimulate a region of the patient tissue that is different, at least in part, from a region of the patient tissue stimulated prior to the adjustment. Alternatively or additionally, the biosignal is indicative of a particular patient activity and the adjustment is a pre-determined adjustment selected for the particular patient activity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Patent Application Ser. No. 62/061,069, filed Oct. 7, 2014,which is incorporated herein by reference.

FIELD

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationsystems that include devices or methods for electrical stimulation whichutilize feedback from one or more sensors to adjust stimulationparameters, as well as methods of making and using the electricalstimulation systems.

BACKGROUND

Implantable electrical stimulation systems have proven therapeutic in avariety of diseases and disorders. For example, spinal cord stimulationsystems have been used as a therapeutic modality for the treatment ofchronic pain syndromes. Peripheral nerve stimulation has been used totreat chronic pain syndrome and incontinence, with a number of otherapplications under investigation. Functional electrical stimulationsystems have been applied to restore some functionality to paralyzedextremities in spinal cord injury patients.

Stimulators have been developed to provide therapy for a variety oftreatments. A stimulator can include a control module (with a pulsegenerator), one or more leads, and an array of stimulator electrodes oneach lead. The stimulator electrodes are in contact with or near thenerves, muscles, or other tissue to be stimulated. The pulse generatorin the control module generates electrical pulses that are delivered bythe electrodes to body tissue.

BRIEF SUMMARY

One embodiment is an electrical stimulation system including animplantable control module for implantation in a body of a patient andhaving an antenna and a processor coupled to the antenna. (In otherembodiments, the control module is an external control module.) Thecontrol module provides electrical stimulation signals to an electricalstimulation lead coupled to the implantable control module forstimulation of patient tissue. The system also includes an externalprogramming unit to communicate with the processor of the implantablecontrol module using the antenna and to provide or update stimulationparameters for production of the electrical stimulation signals; asensor to be disposed on or within the body of the patient and tomeasure a biosignal; and a biosignal processor to communicate with thesensor to receive the biosignal and to generate an adjustment to one ormore of the stimulation parameters based on the biosignal. Theadjustment can be configured and arranged to steer the electricalstimulation signals to stimulate a region of the patient tissue that isdifferent, at least in part, from a region of the patient tissuestimulated prior to the adjustment. Alternatively or additionally, thebiosignal is indicative of a particular patient activity and theadjustment is a pre-determined adjustment selected for the particularpatient activity.

In at least some embodiments, the external programming unit includes thebiosignal processor. In at least some embodiments, the biosignalprocessor is configured and arranged for communication with the externalprogramming unit to deliver the adjustment to the external programmingunit. In at least some embodiments, the sensor is disposed on thecontrol module.

In at least some embodiments, the system also includes a lead coupleableto the control module and having electrodes for delivering theelectrical stimulation signals to the patient tissue. In at least someembodiments, the sensor is disposed on the lead.

In at least some embodiments, the biosignal processor is configured andarranged to perform the following actions: receive the biosignal fromthe sensor; and determine the adjustment to one or more stimulationparameters based on the biosignal. In at least some embodiments, thebiosignal processor is configured and arranged to perform the additionalfollowing action: deliver the adjustment to one of the externalprogramming unit or the control module.

In at least some embodiments, the adjustment is provided to the controlnodule automatically and without user intervention.

Another embodiment is an electrical stimulation system including asensor to be disposed on or within the body of the patient and tomeasure a biosignal; and a control module having a processor. Thecontrol module provides electrical stimulation signals to an electricalstimulation lead coupled to the control module for stimulation ofpatient tissue. The processor is configured and arranged to communicatewith the sensor to receive the biosignal and to generate an adjustmentto one or more of the stimulation parameters based on the biosignal. Theadjustment can be configured and arranged to steer the electricalstimulation signals to stimulate a region of the patient tissue that isdifferent, at least in part, from a region of the patient tissuestimulated prior to the adjustment. Alternatively or additionally, thebiosignal is indicative of a particular patient activity and theadjustment is a pre-determined adjustment selected for the particularpatient activity.

In at least some embodiments, the control module is an implantablecontrol module configured and arranged for implantation in a body of apatient, the implantable control module further comprising an antennacoupled to the processor. In at least some embodiments, the sensor isdisposed on the control module. In other embodiments, the control moduleis an external control module.

In at least some embodiments, the processor is configured and arrangedto perform the following actions: receive the biosignal from the sensor;and determine the adjustment to one or more stimulation parameters basedon the biosignal.

In at least some embodiments, the system also includes a lead coupleableto the control module and comprising a plurality of electrodes fordelivering the electrical stimulation signals to the patient tissue. Inat least some embodiments, the sensor is disposed on the lead.

Yet another embodiment is a non-transitory computer-readable mediumhaving processor-executable instructions for adjusting one or morestimulation parameters, the processor-executable instructions wheninstalled onto a device enable the device to perform actions, including:receive a biosignal from one or more sensors; and determine anadjustment to the one or more stimulation parameters based on thebiosignal. The adjustment can be configured and arranged to steer theelectrical stimulation signals to stimulate a region of the patienttissue that is different, at least in part, from a region of the patienttissue stimulated prior to the adjustment. Alternatively oradditionally, the biosignal is indicative of a particular patientactivity and the adjustment is a pre-determined adjustment selected forthe particular patient activity.

In at least some embodiments, the processor-executable instructions wheninstalled onto a device enable the device to perform the followingadditional action: deliver the adjustment to one of an externalprogramming unit or a control module.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1 is a schematic block diagram of one embodiment of an electricalstimulation system, according to the invention;

FIG. 2 is a schematic block diagram of another embodiment of anelectrical stimulation system, according to the invention;

FIG. 3 is a schematic block diagram of another embodiment of anelectrical stimulation system, according to the invention;

FIG. 4 is a schematic block diagram of one embodiment of an externalprogramming unit, according to the invention;

FIG. 5 is a schematic block diagram of one embodiment of a processingunit, according to the invention;

FIG. 6 is a flowchart of one embodiment of a method for adjustingstimulation parameters, according to the invention;

FIG. 7 is a flowchart of one embodiment of a method for testing a rangeof stimulation parameters, according to the invention;

FIG. 8 is a flowchart of one embodiment of a method for requestingpatient authorization for using patient data, according to theinvention;

FIG. 9 is a schematic view of one embodiment of an electricalstimulation system that includes a paddle lead electrically coupled to acontrol module, according to the invention;

FIG. 10 is a schematic view of one embodiment of an electricalstimulation system that includes a percutaneous lead electricallycoupled to a control module, according to the invention;

FIG. 11A is a schematic view of one embodiment of the control module ofFIG. 9 configured and arranged to electrically couple to an elongateddevice, according to the invention; and

FIG. 11B is a schematic view of one embodiment of a lead extensionconfigured and arranged to electrically couple the elongated device ofFIG. 10 to the control module of FIG. 9, according to the invention.

DETAILED DESCRIPTION

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationsystems that include devices or methods for electrical stimulation whichutilize feedback from one or more sensors to adjust stimulationparameters, as well as methods of making and using the electricalstimulation systems.

Suitable implantable electrical stimulation systems include, but are notlimited to, a least one lead with one or more electrodes disposed alonga distal end of the lead and one or more terminals disposed along theone or more proximal ends of the lead. Leads include, for example,percutaneous leads, paddle leads, and cuff leads. Examples of electricalstimulation systems with leads are found in, for example, U.S. Pat. Nos.6,181,969; 6,516,227; 6,609,029; 6,609,032; 6,741,892; 7,949,395;7,244,150; 7,672,734; 7,761,165; 7,974,706; 8,175,710; 8,224,450; and8,364,278; and U.S. Patent Application Publication No. 2007/0150036, allof which are incorporated by reference.

An electrical stimulation system can include one or more sensors thatcan measure a functional response to electrical stimulation treatment.The measurements can be used in an automated or semi-automated manner toalter one or more stimulation parameters to enhance the treatment. In atleast some embodiments, the system may perform these measurements underone or more conditions such as, for example, during a programmingsession; at regular or irregular intervals during operation of thesystem; or when initiated by a clinician, patient, or other individual.

In at least some embodiments, the electrical stimulation system can havea closed-loop feedback function using the one or more sensors and therespective measurements. The feedback function may be automated orsemi-automated. In at least some embodiments, the feedback function maybe initiated under one or more conditions such as, for example, during aprogramming session; at regular or irregular intervals during operationof the system; or when directed by a clinician, patient, or otherindividual.

In at least some embodiments, the measurements can be used to steer theelectrical stimulation (for example, the electrical current). Steeringcan be performed by, for example, altering the selection of electrode(s)that provide the electrical stimulation; altering the amplitude (orother stimulation parameters such as frequency or duration) ofstimulation provided by given electrodes; or the like or any combinationthereof. In at least some embodiments, steering of the electricalstimulation can include multiple timing channels which utilize theelectrodes of the lead to generate different electric fields. Theelectric fields for the different timing channels can be interleavedtemporally to alter the electrical stimulation of the patient tissue.Stimulation steering can be used to alter the electric field produced bythe system and to alter the portion of patient tissue being stimulatedor the amount of stimulation provided to a region of patient tissue.This can tailor the stimulation to the patient or to the currentcondition of the patient. Any combination of these steering methods canalso be employed.

In at least some embodiments, one or more sensors can be used todetermine patient postural, positional, or activity changes or todetermine changes in disease or disorder progression or modality, orchanges in the stimulation system. These measurements can be used toalter one or more electrical stimulation parameters. The system mayperform these measurements under one or more conditions such as, forexample, during a programming session; at regular or irregular intervalsduring operation of the system; or when directed by a clinician,patient, or other individual. In at least some embodiments, theelectrical stimulation system can have a closed-loop feedback functionthat allows the system to alter stimulation as a result of changes inpatient activity, changes in the disease or disorder, or changes to thecomponents of the system or their surroundings.

FIG. 1 illustrates schematically one embodiment of an electricalstimulation system 100 that includes an implantable control module(e.g., an implantable electrical stimulator or implantable pulsegenerator) 102, one or more leads 108 with electrodes, one or moreexternal programming units 106, one or more sensors 107, and aprocessing unit 104. Alternatively, the implantable control module 102can be part of a microstimulator with the electrodes disposed on thehousing of the microstimulator. The microstimulator may not include alead or, in other embodiments, a lead may extend from themicrostimulator. As yet another alternative, the control module can beexternal to the patient. One example of an external control module is anexternal trial stimulator that can be used temporarily during theimplantation procedure to test stimulation using the lead.

It will be understood that the electrical stimulation system can includemore, fewer, or different components and can have a variety of differentconfigurations including those configurations disclosed in thereferences cited herein. For example, although FIG. 1 illustrates oneexternal programming unit 106, one control module 102, and one sensor107, it will be understood that the system can include more than oneexternal programming unit, more than one control module, more than onesensor, or any combination thereof.

The lead 108 is coupled, or coupleable, to the implantable controlmodule 102. The implantable control module 102 includes a processor 110,an antenna 112 (or other communications arrangement), a power source114, and a memory 116 as illustrated in FIG. 1.

FIGS. 2 and 3 illustrate other embodiments in which the processing unitis omitted and the external programming unit 106, sensor(s) 107, orcontrol module 102 or any combination thereof can perform the functionsof the processing unit. In the embodiment of FIG. 2, the sensor 107 isin communication with the external programming unit 106. In theembodiment of FIG. 3, the sensor 107 is in communication with thecontrol module 102.

One example of an external programming unit 106 is illustrated in FIG. 4and includes a processor 160, a memory 162, a communications arrangement164 (such as an antenna or any other suitable communications device suchas those described below), and a user interface 166. Suitable devicesfor use as an external programming unit can include, but are not limitedto, a computer, a tablet, a mobile telephone, a personal desk assistant,a dedicated device for external programming, remote control, or thelike. It will be understood that the external programming unit 106 caninclude a power supply or receive power from an external source or anycombination thereof. The external programming unit 106 can be a homestation or unit at a clinician's office or any other suitable device. Insome embodiments, the external programming unit 106 can be a device thatis worn on the skin of the user or can be carried by the user and canhave a form similar to a pager, cellular phone, or remote control, ifdesired. The external programming unit 106 can be any unit that canprovide information to the control module 102. One example of a suitableexternal programming unit 106 is a computer operated by the clinician orpatient to send signals to the control module 102. Another example is amobile device or an application on a mobile device that can send signalsto the control module 102

One example of a processing unit 104 is illustrated in FIG. 5 andincludes a processor 140, a memory 142, a communications arrangement 144(such as an antenna or any other suitable communications device such asthose described below), and an optional user interface 146. Suitabledevices for use as a processing unit can include, but are not limitedto, a computer, a tablet, a server or server farm, or the like. It willbe understood that the processing unit 104 can include a power supply orreceive power from an external source or any combination thereof.

Methods of communication between devices or components of a system caninclude wired (including, but not limited to, USB, mini/micro USB, HDMI,and the like) or wireless (e.g., RF, optical, infrared, near fieldcommunication (NIT), (Bluetooth™, or the like) communications methods orany combination thereof. By way of further example, communicationmethods can be performed using any type of communication media or anycombination of communication media including, but not limited to, wiredmedia such as twisted pair, coaxial cable, fiber optics, wave guides,and other wired media and wireless media such as acoustic, RF, optical,infrared, NEC, Bluetooth™ and other wireless media. These communicationmedia can be used for communications units 144, 164 or as antenna 112 oras an alternative or supplement to antenna 112.

Turning to the control module 102, some of the components (for example,a power source 114, an antenna 112, and a processor 110) of theelectrical stimulation system can be positioned on one or more circuitboards or similar carriers within a sealed housing of the control module(implantable pulse generator,) if desired. Any power source 114 can beused including, for example, a battery such as a primary battery or arechargeable battery. Examples of other power sources include supercapacitors, nuclear or atomic batteries, mechanical resonators, infraredcollectors, thermally-powered energy sources, flexural powered energysources, bioenergy power sources, fuel cells, bioelectric cells, osmoticpressure pumps, and the like including the power sources described inU.S. Pat. No. 7,437,193, incorporated herein by reference.

As another alternative, power can be supplied by an external powersource through inductive coupling via the antenna 112 or a secondaryantenna. The external power source can be in a device that is mounted onthe skin of the user or in a unit that is provided near the user on apermanent or periodic basis.

If the power source 114 is a rechargeable battery, the battery may berecharged using the antenna 112, if desired. Power can be provided tothe battery for recharging by inductively coupling the battery throughthe antenna to a recharging unit external to the user.

A stimulation signal, such as electrical current in the form ofelectrical pulses, is emitted by the electrodes of the lead 108 (or amicrostimulator) to stimulate neurons, nerve fibers, muscle fibers, orother body tissues near the electrical stimulation system. Examples ofleads are described in more detail below. The processor 110 is generallyincluded to control the timing and electrical characteristics of theelectrical stimulation system. For example, the processor 110 can, ifdesired, control one or more of the timing, frequency, strength,duration, and waveform of the pulses. In addition, the processor 110 canselect which electrodes can be used to provide stimulation, if desired.In some embodiments, the processor 110 selects which electrode(s) arecathodes and which electrode(s) are anodes. In some embodiments, theprocessor 110 is used to identify which electrodes provide the mostuseful stimulation of the desired tissue.

With respect to the control module 102, external programming unit 106,and database unit 104, any suitable processor 110, 140, 160 can be usedin these devices. For the control module 102, the processor 110 iscapable of receiving and interpreting instructions from an externalprogramming unit 106 that, for example, allows modification of pulsecharacteristics. In the illustrated embodiment, the processor 110 iscoupled to the antenna 112. This allows the processor 110 to receiveinstructions from the external programming unit 106 to, for example,direct the pulse characteristics and the selection of electrodes, ifdesired. The antenna 112, or any other antenna described herein, canhave any suitable configuration including, but not limited to, a coil,looped, or loopless configuration, or the like. In one embodiment, theantenna 112 is capable of receiving signals (e.g., RF signals) from theexternal programming unit 106 or sensor 107.

The signals sent to the processor 110 via the antenna 112 can be used tomodify or otherwise direct the operation of the electrical stimulationsystem. For example, the signals may be used to modify the pulses of theelectrical stimulation system such as modifying one or more of pulseduration, pulse frequency, pulse waveform, and pulse strength. Thesignals may also direct the control module 102 to cease operation, tostart operation, to start charging the battery, or to stop charging thebattery.

Optionally, the control module 102 may include a transmitter (not shown)coupled to the processor 110 and the antenna 112 for transmittingsignals back to the external programming unit 106 or another unitcapable of receiving the signals. For example, the control module 102may transmit signals indicating whether the control module 102 isoperating properly or not or indicating when the battery needs to becharged or the level of charge remaining in the battery. The processor110 may also be capable of transmitting information about the pulsecharacteristics so that a user or clinician can determine or verify thecharacteristics.

Any suitable memory 116, 142, 162 can be used for the respectivecomponents of the system 100. The memory 116, 142, 162 illustrates atype of computer-readable media, namely computer-readable storage media.Computer-readable storage media may include, but is not limited to,nonvolatile, removable, and non-removable media implemented in anymethod or technology for storage of information, such as computerreadable instructions, data structures, program modules, or other data.Examples of computer-readable storage media include RAM, ROM, EEPROM,flash memory, or other memory technology, CD-ROM, digital versatiledisks (“DVD”) or other optical storage, magnetic cassettes, magnetictape, magnetic disk storage or other magnetic storage devices, or anyother medium which can be used to store the desired information andwhich can be accessed by a computing device.

Communication methods provide another type of computer readable media;namely communication media. Communication media typically embodiescomputer-readable instructions, data structures, program modules, orother data in a modulated data signal such as a carrier wave, datasignal, or other transport mechanism and include any informationdelivery media. The terms “modulated data signal.” and “carrier-wavesignal” includes a signal that has one or more of its characteristicsset or changed in such a manner as to encode information, instructions,data, and the like, in the signal. By way of example, communicationmedia includes wired media such as twisted pair, coaxial cable, fiberoptics, wave guides, and other wired media and wireless media such asacoustic, RF, infrared, and other wireless media.

The user interface 166 of the external programming unit 106 and optionaluser interface 146 of the processing unit 104 can be, for example, akeyboard, mouse, touch screen, track ball, joystick, voice recognitionsystem, or any combination thereof, and the like. Alternatively oradditionally, the user interface 166 of the external programming unit106 can include one or more microphones, sensors, cameras, or the liketo obtain clinician or patient input. For example, the clinician orpatient may provide input verbally (e.g. voice command recognition,voice recordings) or visually (e.g. video of patient, non-touch gesturerecognition, or the like). In at least some embodiments, patientfeedback can be provided by the clinician or other user through theexternal programming unit 106.

The one or more sensors 107 can be any suitable sensors for measuring abiosignal (which can include a variable biological condition such as,for example, skin resistance, skin or tissue impedance, temperature, orthe like). Examples of biosignals include EEG, electrocochleograph(ECOG), electromyography, skin resistance, skin or tissue impedance,muscle tone, heart rate, ECG, blood pressure, electrical signalstraversing the spinal cord or a nerve or group of nerves, tremors orother movement (which can be measured using, for example, displacement,velocity, acceleration, direction of movement, and the like), musclecontraction or relaxation, vibration, temperature, breathing, oxygenlevels, chemical concentrations, gait, skin tone, or the like.

Any sensor suitable for measuring the corresponding biosignal can beused. The sensor can be a mechanical, electrical, chemical, orbiological sensor or any combination thereof. The sensor can be insertedin, implanted in, positioned on, or otherwise coupled to the body of thepatient. In some embodiments, at least one sensor is provided on thelead or control module and can be, for example, a separate recordingelectrode for recording electrical signals or can be one or morestimulating electrodes that also are used for recording electricalsignals. In other embodiments, the sensor can be attached to the body ofthe patient using, for example, a band, cuff, belt, clamp, clip,friction, adhesive, or the like or any combination thereof. In someembodiments, the sensor can be provided on, or attached to, the externalprogramming unit or a patient remote control or a charging unit for thecontrol module.

The sensor 107 can be in communication with the external programmingunit 106, the control module 102, the processing unit 104, or anycombination thereof. Such communication can be wired or wireless or anycombination thereof using any of the communication methods describedabove. In at least some embodiments, the sensor 107 can include aprocessor, a memory, or both.

In at least some embodiments, the sensor 107 is deployed and used onlyduring a programming session. In other embodiments, the sensor 107 maybe deployed on or within the patient for an extended period of time (forexample, at least one day, one week, one month, six months, one year, orlonger). In at least some embodiments, the sensor 107 may be in regularor constant communication with the control module 102 or externalprogramming unit 106. In at least some embodiments, the sensor 107 maycontact the control module 102, external programming unit 106, orprocessing unit 104 when requested, when a change in the biosignalexceeds a threshold, at regular or irregular intervals, or anycombination thereof.

As an example, in at least some embodiments, the system includes asensor that detects or measures muscle tremors or rigidity. For example,the sensor can be an accelerometer or the like and can be a fingertipsensor or a sensor disposed on a band, belt, adhesive, or other fastenerso that the sensor can be mounted on the leg, arm, or other portion ofthe patient. Such a sensor could be used, for example, with anelectrical stimulation system for treating Parkinson's disease,essential tremor, dystonia, hemiballismus, Tourette's syndrome.Huntington's disease, urge incontinence, or any other disease ordisorder that causes muscle tremors or other involuntary muscle actionsor rigidity or for treating symptoms such as, for example, tremor,rigidity, bradykinesia, freezing of gait, dyskinesias, or the like.

As another example, in at least some embodiments, the system includes asensor that detects or measures blood pressure. For example, the sensorcan be a cuff or other blood pressure measurement device, such as afingertip sensor or a sensor disposed on a band, belt, adhesive, orother fastener so that the sensor can be mounted on the leg, arm, orother portion of the patient. Such a sensor could be used, for example,with an electrical stimulation system for carotid sinus stimulation,deep brain stimulation, or the like.

Yet another example, in at least some embodiments, the sensor includes asensor that detects or measures heart rate and parameters associatedheart rate, such as heart rate variability (HR variability). HRvariability can be correlated with anxiety or sources that cause anxiety(pain, PTSD, OCD, and the like). Heart Rate is also a surrogate foractivity monitoring. In at least some embodiments, the heart rate can bemonitored by a sensor disposed on a lead implanted in or near the spinalcord and used for electrical stimulation of the spinal cord.

In at least some embodiments, the system includes a sensor that detectsor measures movement. For example, the sensor can be a globalpositioning sensor (GPS), accelerometer, heart rate or pulse ratemonitor, blood pressure cuff or other blood pressure measurement devicesuch as a fingertip sensor, or the like. Such a sensor could be used,for example, with an electrical stimulation system to adjust one or morestimulation parameters based on patient activity. For example, thesensor may detect when a patient is walking, running, climbing, driving,sitting, resting, sleeping, or the like. Sleeping longevity andinterruptions to sleep may be very relevant for some indications. In atleast some instances, Parkinson's patients have shorter sleep. Also,individuals with overactive bladder or interstitial cystitis havedisrupted sleep for urination. Sensing attributes of sleep can be usedto adjust one or more stimulation parameters.

The electrical stimulation system 100 can use the measurements from thesensor(s) 107 to modify one or more stimulation parameters. In someembodiments, the modification of stimulation parameters results insteering the electrical stimulation (for example, a stimulation current)to stimulate different portions of the patient tissue or produce adifferent stimulation field. In some embodiments, this steering can beaccomplished by changing the selection of one or more electrodes on thelead used to deliver the electrical stimulation or adjusting therelative amplitudes, frequency, or duration of stimulation from theelectrode(s) or any combination thereof. In other embodiments, one ormore stimulation parameters can be changed including, but not limitedto, amplitude, pulse width, pulse frequency, electrode configuration,electrode polarity, and the like. In at least some embodiments, steeringof the electrical stimulation can include multiple timing channels whichutilize the electrodes of the lead to generate different electricfields. The electric fields for the different timing channels can beinterleaved temporally to alter the electrical stimulation of thepatient tissue.

In at least some embodiments, the measurements from the sensor(s) 107are provided to the processing unit 104. The processing unit 104includes an algorithm or other computer program that utilizes the sensormeasurements and the current stimulation parameters and, optionally,other information regarding the patient, disease or disorder, and thelike to determine adjustment to one or more of the stimulationparameters. The processing unit 104 can communicate the adjustment to aclinician or other user or to the external programming unit 106 orcontrol module 102.

In other embodiments, the external programming unit 106 or controlmodule 102 receives the measurements from the sensor(s) 107 and includesan algorithm or other computer program that utilizes the sensormeasurements and the current stimulation parameters and, optionally,other information regarding the patient, disease or disorder, and thelike to determine adjustment to one or more of the stimulationparameters. In yet other embodiments, the sensor includes the algorithmor other computer program that determines adjustment to one or more ofthe stimulation parameters based on the sensor measurements.

In addition to the sensor measurements, the algorithm or computerprogram also receives the current stimulation parameters from, forexample, the external programming unit or the control module or anyother suitable source. The system can also incorporate one or more ofmedication information, demographics (for example, age, gender,ethnicity, height, weight, or the like), disease-specific details (forexample, pain etiology(ies), number of prior back surgeries, relevantdiagnoses, imaging findings, or the like) in the information used todetermine adjustments to the stimulation parameters. The algorithm orcomputer program may determine adjustments based on patient-specificresponse to previous adjustments, based on population response toprevious adjustments, based on patient activity or disease/disorderstatus determined from the sensor measurements, or any combinationthereof. In at least some embodiments, the clinician may direct thepatient to perform a particular activity (for example, finger tapping,drawing a spiral or other shape, walking, or the like) and the systemuses the sensor measurements during this activity to evaluate anddetermine adjustments to the stimulation parameters.

In at least some embodiments, the system may utilize a step-wisemethodology to altering the stimulation parameters. For example, thesystem may alter one or more stimulation parameters based on the sensormeasurements and then observe the results of the alteration as measuredusing the sensor (or based on other input such as patient or clinicianfeedback.) In at least some embodiments, the system waits for a latencyperiod to allow the clinical effect to be measureable by the sensor. Forexample, for tremor response, the latency period may be less than oneminute or five minutes. For blood pressure measurements, the latencyperiod may be five or ten minutes or longer.

In some embodiments, the system may have the objective of improving oroptimizing stimulation to produce a desired sensed clinical effect ormay improve or co-optimize multiple sensed clinical effects or mayimprove or co-optimize one or more clinical effects and energy usage.Any suitable algorithmic technique can be used including, but notlimited to, brute force parameter space searching, gradient searchmethods, genetic or stimulated annealing methods, machine learning orsupport vector machine methods, or the like. Such general techniques foralgorithms are known.

In some embodiments, the system may have one or more specificstimulation parameter sets designated for specific patient activities,disease states, or the like. When the system detects the specificpatient activity (e.g., walking, running, resting, sleeping, or thelike) or disease state using the sensor measurements, the system can setthe stimulation parameters to the corresponding set. In someembodiments, the system may also determine a preferred set ofstimulation parameters associated with patient activity, disease state,or sensor measurement value or range using the algorithmic techniquesdescribed above and may adjust the stimulation parameters to thatpreferred set upon detecting the patient activity, disease state, orsensor measurement value or range.

FIG. 6 is a flowchart of one embodiment of a method of adjustingstimulation parameters. In step 602, a biosignal is sensed by one ormore sensors. In some embodiments, more than one biosignal can be sensedor biosignals from two or more locations on the body of the patient canbe sensed.

In step 604, the biosignal is analyzed and an adjustment to one or morestimulation parameters is generated. Examples of stimulation parametersthat can be adjusted include, but are not limited to, pulse frequency,pulse width, electrode field selection (anodes and cathodes which maycan also affect the location of stimulation), pulse amplitude, pulseburst frequency or duration, pulse patterns, other pulse timingparameters, and the like. The analysis and generation of the adjustmentcan be performed by the processing unit 104, external programming unit106, control module 102, or sensor 107 or any combination thereof. Thebiosignal can be communicated to the processing unit 104, externalprogramming unit 106, control module 102, or sensor 107 or anycombination thereof.

In step 606, a user (such as a clinician or patient) inputs the adjustedstimulation parameter(s) into the external programming unit 106. Thisprocess is semi-automated because it includes participation by the user.This participation may be desirable to provide user analysis of theadjusted stimulation parameters. This procedure may be useful, forexample, during a control module programming session with a clinician.In such a procedure, the patient may also provide feedback regarding theadjusted stimulation.

In step 608, the external programming unit 106 transmits the adjustedstimulation parameters to the control module 102. The control module 102then proceeds to deliver electrical stimulation using the adjustedstimulation parameters.

In step, 610, it is determined whether to repeat the process. If so,steps 602-610 are repeated. If not, the method terminates. In someembodiments, the process will automatically repeat without any formaldecision to do so. In some embodiments, the process may repeat atregular or irregular intervals.

FIG. 7 is a flowchart of another embodiment of a method of adjustingstimulation parameters. In step 702, a biosignal is sensed by one ormore sensors. In some embodiments, more than one biosignal can be sensedor biosignals from two or more locations on the body of the patient canbe sensed.

In step 704, the biosignal is analyzed and an adjustment to one or morestimulation parameters is generated. Examples of stimulation parametersthat can be adjusted include, but are not limited to, pulse frequency,pulse width, electrode field selection (anodes and cathodes which maycan also affect the location of stimulation), pulse amplitude, pulseburst frequency or duration, pulse patterns, other pulse timingparameters, and the like. The analysis and generation of the adjustmentcan be performed by the processing unit 104, external programming unit106, control module 102, or sensor 107 or any combination thereof. Thebiosignal can be communicated to the processing unit 104, externalprogramming unit 106, control module 102, or sensor 107 or anycombination thereof.

In step 706 the stimulation parameter(s) are automatically adjusted atthe external programming unit 106. In some embodiments, such as during acontrol module programming session, the external programming unit 106may optionally display the adjusted parameters so that the clinician orpatient can halt the process, if desired, or observe or direct the pathof tested parameters.

In step 708, the external programming unit 106 transmits the adjustedstimulation parameters to the control module 102. The control module 102then proceeds to deliver electrical stimulation using the adjustedstimulation parameters.

In step, 710, it is determined whether to repeat the process. If so,steps 702-710 are repeated. If not, the method terminates. In someembodiments, the process will automatically repeat without any formaldecision to do so. In some embodiments, the process may repeat atregular or irregular intervals.

FIG. 8 is a flowchart of another embodiment of a method of adjustingstimulation parameters. In step 802, a biosignal is sensed by one ormore sensors. In some embodiments, more than one biosignal can be sensedor biosignals from two or more locations on the body of the patient canbe sensed.

In step 804, the biosignal is analyzed and an adjustment to one or morestimulation parameters is generated. Examples of stimulation parametersthat can be adjusted include, but are not limited to, pulse frequency,pulse width, electrode field selection (anodes and cathodes which maycan also affect the location of stimulation), pulse amplitude, pulseburst frequency or duration, pulse patterns, other pulse timingparameters, and the like. The analysis and generation of the adjustmentcan be performed by the processing unit 104, external programming unit106, control module 102, or sensor 107 or any combination thereof. Thebiosignal can be communicated to the processing unit 104, externalprogramming unit 106, control module 102, or sensor 107 or anycombination thereof.

In step 806, the stimulation parameters are automatically adjusted inthe control module 102. The control module 102 then proceeds to deliverelectrical stimulation using the adjusted stimulation parameters. Thisprocess may be particularly useful where the control module 102 receivesthe measurements or the adjustment to the stimulation parametersdirectly from the sensor 107.

In step, 810, it is determined whether to repeat the process. If so,steps 802-810 are repeated. If not, the method terminates. In someembodiments, the process will automatically repeat without any formaldecision to do so. In some embodiments, the process may repeat atregular or irregular intervals.

The processes illustrated in FIGS. 6-8 can be used as a feedback loop toadjust stimulation parameters. The feedback loop may be part of aprogramming session. Alternatively or additionally, the electricalstimulation system may initiate the feedback loop on a regular orirregular basis or when requested by a user, clinician, or otherindividual to adjust stimulation parameters.

It will be understood that the system can include one or more of themethods described hereinabove with respect to FIGS. 6-8 in anycombination. The methods, systems, and units described herein may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Accordingly, the methods, systems,and units described herein may take the form of an entirely hardwareembodiment, an entirely software embodiment or an embodiment combiningsoftware and hardware aspects. The methods described herein can beperformed using any type of processor or any combination of processorswhere each processor performs at least part of the process.

It will be understood that each block of the flowchart illustrations,and combinations of blocks in the flowchart illustrations and methodsdisclosed herein, can be implemented by computer program instructions.These program instructions may be provided to a processor to produce amachine, such that the instructions, which execute on the processor,create means for implementing the actions specified in the flowchartblock or blocks or described for the control modules, externalprogramming units, sensors, systems and methods disclosed herein. Thecomputer program instructions may be executed by a processor to cause aseries of operational steps to be performed by the processor to producea computer implemented process. The computer program instructions mayalso cause at least some of the operational steps to be performed inparallel. Moreover, some of the steps may also be performed across morethan one processor, such as might arise in a multi-processor computersystem. In addition, one or more processes may also be performedconcurrently with other processes, or even in a different sequence thanillustrated without departing from the scope or spirit of the invention.

The computer program instructions can be stored on any suitablecomputer-readable medium including, but not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (“DVD”) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by a computing device.

FIG. 9 illustrates one embodiment of a control module 402 and lead 403.The lead 403 includes a paddle body 444 and one or more lead bodies 446.In FIG. 9, the lead 403 is shown having two lead bodies 446. It will beunderstood that the lead 403 can include any suitable number of leadbodies including, for example, one, two, three, four, five, six, seven,eight or more lead bodies 446. An array of electrodes 433, such aselectrode 434, is disposed on the paddle body 444, and one or moreterminals (e.g., 560 in FIGS. 11A and 11B) are disposed along each ofthe one or more lead bodies 446. In at least some embodiments, the leadhas more electrodes than terminals.

FIG. 10 illustrates schematically another embodiment in which the lead403 is a percutaneous lead. In FIG. 10, the electrodes 434 are showndisposed along the one or more lead bodies 446. In at least someembodiments, the lead 403 is isodiametric along a longitudinal length ofthe lead body 446.

The lead 403 can be coupled to the implantable control module 402 in anysuitable manner. In FIG. 9, the lead 403 is shown coupling directly tothe implantable control module 402. In at least some other embodiments,the lead 403 couples to the implantable control module 402 via one ormore intermediate devices (500 in FIGS. 11A and 11B). For example, in atleast some embodiments one or more lead extensions 524 (see e.g., FIG.11B) can be disposed between the lead 403 and the implantable controlmodule 402 to extend the distance between the lead 403 and theimplantable control module 402. Other intermediate devices may be usedin addition to, or in lieu of, one or more lead extensions including,for example, a splitter, an adaptor, or the like or combinationsthereof. It will be understood that, in the case where the electricalstimulation system includes multiple elongated devices disposed betweenthe lead 403 and the implantable control module 402, the intermediatedevices may be configured into any suitable arrangement.

In FIG. 10, the electrical stimulation system 400 is shown having asplitter 457 configured and arranged for facilitating coupling of thelead 403 to the implantable control module 402. The splitter 457includes a splitter connector 458 configured to couple to a proximal endof the lead 403, and one or more splitter tails 459 a and 459 bconfigured and arranged to couple to the implantable control module 402(or another splitter, a lead extension, an adaptor, or the like).

The implantable control module 402 includes a connector housing 448 anda sealed electronics housing 450. An electronic subassembly 452 (whichincludes the processor 110 (see, FIGS. 1-3) and the power source 414 aredisposed in the electronics housing 450. A connector 445 is disposed inthe connector housing 448. The connector 445 is configured and arrangedto make an electrical connection between the lead 403 and the electronicsubassembly 452 of the implantable control module 402.

The electrical stimulation system or components of the electricalstimulation system, including the paddle body 444, the one or more ofthe lead bodies 446, and the implantable control module 402, aretypically implanted into the body of a patient. The electricalstimulation system can be used for a variety of applications including,but not limited to deep brain stimulation, neural stimulation, spinalcord stimulation, muscle stimulation, and the like.

The electrodes 434 can be formed using any conductive, biocompatiblematerial. Examples of suitable materials include metals, alloys,conductive polymers, conductive carbon, and the like, as well ascombinations thereof. In at least some embodiments, one or more of theelectrodes 434 are formed from one or more of: platinum, platinumiridium, palladium, palladium rhodium, or titanium.

Any suitable number of electrodes 434 can be disposed on the leadincluding, for example, four, five, six, seven, eight, nine, ten,eleven, twelve, fourteen, sixteen, twenty-four, thirty-two, or moreelectrodes 434. In the case of paddle leads, the electrodes 434 can bedisposed on the paddle body 444 in any suitable arrangement. In FIG. 9,the electrodes 434 are arranged into two columns, where each column haseight electrodes 434.

The electrodes of the paddle body 444 (or one or more lead bodies 446)are typically disposed in, or separated by, a non-conductive,biocompatible material such as, for example, silicone, polyurethane,polyetheretherketone (“PEEK”), epoxy, and the like or combinationsthereof. The one or more lead bodies 446 and, if applicable, the paddlebody 444 may be formed in the desired shape by any process including,for example, molding (including injection molding), casting, and thelike. The non-conductive material typically extends from the distal endsof the one or more lead bodies 446 to the proximal end of each of theone or more lead bodies 446.

In the case of paddle leads, the non-conductive material typicallyextends from the paddle body 444 to the proximal end of each of the oneor more lead bodies 446. Additionally, the non-conductive, biocompatiblematerial of the paddle body 444 and the one or more lead bodies 446 maybe the same or different. Moreover, the paddle body 444 and the one ormore lead bodies 446 may be a unitary structure or can be formed as twoseparate structures that are permanently or detachably coupled together.

One or more terminals (e.g., 560 in FIGS. 11A-11B) are typicallydisposed along the proximal end of the one or more lead bodies 446 ofthe electrical stimulation system 400 (as well as any splitters, leadextensions, adaptors, or the like) for electrical connection tocorresponding connector contacts (e.g., 564 in FIGS. 11A-11B). Theconnector contacts are disposed in connectors (e.g., 445 in FIGS. 9-11B;and 572 FIG. 11B) which, in turn, are disposed on, for example, theimplantable control module 402 (or a lead extension, a splitter, anadaptor, or the like). One or more electrically conductive wires,cables, or the like (i.e., “conductors”—not shown) extend from theterminal(s) to the electrode(s). In at least some embodiments, there isat least one (or exactly one) terminal conductor for each terminal whichextends to at least one (or exactly one) of the electrodes.

The one or more conductors are embedded in the non-conductive materialof the lead body 446 or can be disposed in one or more lumens (notshown) extending along the lead body 446. For example, any of theconductors may extend distally along the lead body 446 from theterminals 560.

FIG. 11A is a schematic side view of one embodiment of a proximal end ofone or more elongated devices 500 configured and arranged for couplingto one embodiment of the connector 445. The one or more elongateddevices may include, for example, one or more of the lead bodies 446 ofFIG. 9, one or more intermediate devices (e.g., a splitter, the leadextension 524 of FIG. 11B, an adaptor, or the like or combinationsthereof), or a combination thereof.

The connector 445 defines at least one port into which a proximal ends446A, 446B of the elongated device 500 can be inserted, as shown bydirectional arrows 562 a, 562 b. In FIG. 11A (and in other figures), theconnector housing 448 is shown having two ports 554 a, 554 b. Theconnector housing 448 can define any suitable number of ports including,for example, one, two, three, four, five, six, seven, eight, or moreports.

The connector 445 also includes one or more connector contacts, such asconnector contact 564, disposed within each port 554 a, 554 b. When theelongated device 500 is inserted into the ports 554 a, 554 b, theconnector contact(s) 564 can be aligned with the terminal(s) 560disposed along the proximal end(s) of the elongated device(s) 500 toelectrically couple the implantable control module 402 to the electrodes(434 of FIG. 9) disposed on the paddle body 445 of the lead 403.Examples of connectors in implantable control modules are found in, forexample, U.S. Pat. Nos. 7,244,150 and 8,224,450, which are incorporatedby reference.

FIG. 11B is a schematic side view of another embodiment that includes alead extension 524 that is configured and arranged to couple one or moreelongated devices 500 (e.g., one of the lead bodies 446 of FIGS. 9 and10, the splitter 457 of FIG. 10, an adaptor, another lead extension, orthe like or combinations thereof) to the implantable control module 402.In FIG. 11B, the lead extension 524 is shown coupled to a single port554 defined in the connector 445. Additionally, the lead extension 524is shown configured and arranged to couple to a single elongated device500. In alternate embodiments, the lead extension 524 is configured andarranged to couple to multiple ports 554 defined in the connector 445,or to receive multiple elongated devices 500, or both.

A lead extension connector 572 is disposed on the lead extension 524. InFIG. 11B, the lead extension connector 572 is shown disposed at a distalend 576 of the lead extension 524. The lead extension connector 572includes a connector housing 578. The connector housing 578 defines atleast one port 530 into which terminal(s) 560 of the elongated device500 can be inserted, as shown by directional arrow 538. The connectorhousing 578 also includes a plurality of connector contacts, such asconnector contact 580. When the elongated device 500 is inserted intothe port 530, the connector contacts 580 disposed in the connectorhousing 578 can be aligned with the terminal(s) 560 of the elongateddevice 500 to electrically couple the lead extension 524 to theelectrodes (434 of FIGS. 9 and 10) disposed along the lead (403 in FIGS.9 and 10).

In at least some embodiments, the proximal end of the lead extension 524is similarly configured and arranged as a proximal end of the lead 403(or other elongated device 500). The lead extension 524 may include oneor more electrically conductive wires (not shown) that electricallycouple the connector contact(s) 580 to a proximal end 548 of the leadextension 524 that is opposite to the distal end 576. The conductivewire(s) disposed in the lead extension 524 can be electrically coupledto one or more terminals (not shown) disposed along the proximal end 548of the lead extension 524. The proximal end 548 of the lead extension524 is configured and arranged for insertion into a connector disposedin another lead extension (or another intermediate device). As shown inFIG. 11B, the proximal end 548 of the lead extension 524 is configuredand arranged for insertion into the connector 445.

The embodiments of FIGS. 9-11B illustrate a control module 402 with aconnector 445 into which a proximal end portion of the lead or leadextension can be removably inserted. It will be recognized, however,that other embodiments of a control module and lead can have the lead orlead extension permanently attached to the control module. Such anarrangement can reduce the size of the control module as the conductorsin the lead can be permanently attached to the electronic subassembly.It will also be recognized that, in at least some embodiments, more thanone lead can be attached to a control module.

The above specification and examples provide a description of themanufacture and use of the invention. Since many embodiments of theinvention can be made without departing from the spirit and scope of theinvention, the invention also resides in the claims hereinafterappended.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. An electrical stimulation system, comprising:an implantable control module configured and arranged for implantationin a body of a patient and comprising an antenna and a processor coupledto the antenna, wherein the control module is configured and arranged toprovide electrical stimulation signals to an electrical stimulation leadcoupled to the implantable control module for stimulation of patienttissue; an external programming unit configured and arranged tocommunicate with the processor of the implantable control module usingthe antenna and to provide or update stimulation parameters forproduction of the electrical stimulation signals; a sensor configuredand arranged to be disposed on or within the body of the patient and tomeasure a biosignal; and a biosignal processor configured and arrangedto communicate with the sensor to receive the biosignal and to generatean adjustment to one or more of the stimulation parameters based on thebiosignal, wherein the adjustment is configured and arranged to steerthe electrical stimulation signals to stimulate a region of the patienttissue that is different, at least in part, from a region of the patienttissue stimulated prior to the adjustment.
 2. The electrical stimulationsystem of claim 1, wherein the external programming unit comprises thebiosignal processor.
 3. The electrical stimulation system of claim 1,wherein the biosignal processor is configured and arranged forcommunication with the external programming unit to deliver theadjustment to the external programming unit.
 4. The electricalstimulation system of claim 1, wherein the biosignal processor isconfigured and arranged to perform the following actions: receive thebiosignal from the sensor; and determine the adjustment to one or morestimulation parameters based on the biosignal.
 5. The electricalstimulation system of claim 4, wherein the biosignal processor isconfigured and arranged to perform the additional following action:deliver the adjustment to one of the external programming unit or thecontrol module.
 6. The electrical stimulation system of claim 1, furthercomprising a lead coupleable to the control module and comprising aplurality of electrodes for delivering the electrical stimulationsignals to the patient tissue.
 7. The electrical stimulation system ofclaim 1, wherein the adjustment is provided to the control moduleautomatically and without user intervention.
 8. An electricalstimulation system, comprising: a sensor configured and arranged to bedisposed on or within the body of the patient and to measure abiosignal; and a control module comprising a processor, wherein thecontrol module is configured and arranged to use stimulation parametersto provide electrical stimulation signals to an electrical stimulationlead coupled to the control module for stimulation of patient tissue,wherein the processor is configured and arranged to communicate with thesensor to receive the biosignal and to generate an adjustment to one ormore of the stimulation parameters based on the biosignal, wherein theadjustment is configured and arranged to steer the electricalstimulation signals to stimulate a region of the patient tissue that isdifferent, at least in part, from a region of the patient tissuestimulated prior to the adjustment.
 9. The electrical stimulation systemof claim 8, wherein the control module is an implantable control moduleconfigured and arranged for implantation in a body of a patient, theimplantable control module further comprising an antenna coupled to theprocessor.
 10. The electrical stimulation system of claim 8, wherein theprocessor is configured and arranged to perform the following actions:receive the biosignal from the sensor; and determine the adjustment toone or more stimulation parameters based on the biosignal.
 11. Theelectrical stimulation system of claim 8, further comprising a leadcoupleable to the control module and comprising a plurality ofelectrodes for delivering the electrical stimulation signals to thepatient tissue.
 12. The electrical stimulation system of claim 11,wherein the sensor is disposed on the lead.
 13. The electricalstimulation system of claim 8, wherein the sensor is disposed on thecontrol module.
 14. An electrical stimulation system, comprising: asensor configured and arranged to be disposed on or within the body ofthe patient and to measure a biosignal; and a control module comprisinga processor, wherein the control module is configured and arranged touse stimulation parameters to provide electrical stimulation signals toan electrical stimulation lead coupled to the control module forstimulation of patient tissue, wherein the processor is configured andarranged to communicate with the sensor to receive the biosignal and togenerate an adjustment to one or more of the stimulation parametersbased on the biosignal, wherein the biosignal is indicative of aparticular patient activity and the adjustment is a pre-determinedadjustment selected for the particular patient activity.
 15. Theelectrical stimulation system of claim 14, wherein the control module isan implantable control module configured and arranged for implantationin a body of a patient, the implantable control module furthercomprising an antenna coupled to the processor.
 16. The electricalstimulation system of claim 14, wherein the processor is configured andarranged to perform the following actions: receive the biosignal fromthe sensor; and determine the adjustment to one or more stimulationparameters based on the biosignal.
 17. The electrical stimulation systemof claim 14, wherein the adjustment is configured and arranged to steerthe electrical stimulation signals to stimulate a region of the patienttissue that is different, at least in part, from a region of the patienttissue stimulated prior to the adjustment.
 18. The electricalstimulation system of claim 14, further comprising a lead coupleable tothe control module and comprising a plurality of electrodes fordelivering the electrical stimulation signals to the patient tissue. 19.The electrical stimulation system of claim 18, wherein the sensor isdisposed on the lead.
 20. The electrical stimulation system of claim 14,wherein the sensor is disposed on the control module.